BACKGROUND
The occurrence of multiple autoimmune neurological disorders in one patient is rare. Here, we present the case of a woman who exhibited clinical features and antibody titers consistent with myasthenia gravis (MG), neuromyelitis optica (NMO), and anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis.
CASE REPORT
A 37-year-old woman with a 10-year history of MG presented with a sudden loss of central vision in her right eye. Magnetic resonance imaging (MRI) revealed new enhancement of the right optic nerve, and additional cervical and thoracic spine scans showed continuous demyelination of the central cord. Given these findings, a primary demyelinating condition was suspected, and an NMO antibody test confirmed the diagnosis. Two years later, the patient developed significant behavioral changes, including neglecting her usual activities and displaying diminished responsiveness. She became mute and uncooperative with commands. Based on clinical suspicion of anti-NMDAR encephalitis, a comprehensive work-up revealed the presence of NMDAR antibodies, confirming the diagnosis. The patient was treated with plasma exchange, resulting in a marked improvement in her encephalopathy.
CONCLUSIONS
Over 12 years, this patient developed clinical manifestations of 3 distinct neurological autoimmune disorders. This case underscores the critical need for clinicians to remain alert to overlapping neurological conditions, enabling timely diagnoses and interventions that can help improve clinical outcomes and prevent unnecessary delays in treatment.

Keywords: Anti-N-Methyl-D-Aspartate Receptor Encephalitis; Autoimmune Diseases of the Nervous System; Myasthenia Gravis; Neurology; Neuromyelitis Optica